package jdbc;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class JDBCDemo6 {
    public static void main(String[] args) {
        try(
                Connection connection=DBUtil.getConnection()
        ) {
            Statement statement=connection.createStatement();
            String sql="SELECT COUNT(*) count " +
                       "FROM class c " +
                       "JOIN student s ON c.id=s.class_id " +
                       "WHERE c.name='1年级1班'";
            ResultSet rs=statement.executeQuery(sql);
            while(rs.next()){
                int count=rs.getInt("count");
                System.out.println("人数:"+count);
            }
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }
}
